A few degrees of planetary warming may not sound alarming but it is. A few microseconds of error don't sound like much but they can mean the difference between navigating a spacecraft successfully to Mars, or not. In this episode Dave talks to Drew Shindell about a web article called " A Degree of Concern: Why Global Temperatures Matter ." Written by NASA Media Specialist Alan Buis, Shindell, a Duke University Atmospheric Physicist was the scientific collaborator on the project which explains